LeetCode 171. Excel Sheet Column Number C语言

Given a column title as appear in an Excel sheet, return its corresponding column number.

For example:

A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28

这一体是其他进制转换为进制的变形；
这里是２６进制转十进制；

int titleToNumber(char* s) {
int num = 0;
int i = 0;
while(*(s+i) != '\0')
{
num *= 26;
num += *(s+i)-'A'+1;
i++;
}
return num;
}